
.row1 div {
    border-bottom: 1px solid #ccc;
    /* border-bottom: 5px solid pink ; */
}
.row1 {
    height: 200px;
}


.row2 div{
    width: 300px;
    height: 200px;
    border :20px solid #ccc;
    text-align: center;
    background-color: powderblue;
    margin: 0 auto;
    padding: 10px;
    background-color: purple;
    
}

.row3 {
    height: 300px;
    display: flex;
    /* 主轴方向 */
    flex-direction:row;
    /* 主轴对齐方式 */
    justify-content: space-between;
    /* 换行 */
    flex-wrap: wrap;
    /* 侧轴对齐方式 */
    align-content: center;
}
.row3 span{
    /* 每行显示4个,因为有margin值 */
    width: 23%;
    height: 100px;
    background-color: pink;
    margin-top: 5px;
    margin-right: 5px;    
}

.row3 span:nth-child(4){
    /* 每行显示4个,因为有margin值 */
    order:1;
}
img {
    width:100%;

    height:100%;
}

.row4 {
    height: 200px;
    display: flex;
    margin-top: 20px;
}
.row4 div:nth-child(1){
    width: 100px;
    background-color: pink;
}
.row4 div:nth-child(3){
    width: 100px;
    background-color: pink;
}
.row4 div:nth-child(2){

    flex:1;
    background-color: grey;
}